@KusangAre you refering to Journey of the spark? It won't come out till 2015.

Yeah, that's Doctor Whooves with the sonic screwdriver and Octavia whacking monsters with her cello. Someone should really animate the comic. And speaking of it, it was revealed that S1 Luna is her weakened form, and the mane 6 don't need those jewelries to utilize the elements of harmony.

It depends on the goals they set to achieve. If they are looking at making it a series sort of like the .MOV series or My Little Portal, then perhaps it would be more advantageous to do 10-15 min animated vids spread over time. However if the goal is to make one big animation with no follow up, then perhaps longer animations would be a good approach in that respect. Though if they are gonna make a long animation, they better put their all into it.